The present invention relates to a control equipment for controlling power generated by a boiling water reactor.
In recent years, proportion of nuclear power generation to the whole tends to be increased. In the near future, it is expected that operation of a nuclear reactor under a base load will be increasingly replaced by a load following operation in which the reactor power is adjustably controlled in dependence on actual power demand.
When the reactor power is to be changed, it is indispensable to selectively determine the manipulating quantity as well as the manipulating means so that the power distribution in the reactor core meets the imposed constraints. In the case of the load following operation described above, the core conditions will undergo change at a high speed. Consequently, the reactor power must be controlled so as to satisfy the constraints by monitoring the power distribution in the reactor core with a correspondingly shortened period.
In order to reflect the monitored power distribution to the power control, estimation of the power distribution in the reactor core has to be realized in a short time span in the order of a few minutes. Actually, however, it takes ten or more minutes to estimate the power distribution in the whole reactor core. In other words, with the hitherto known procedure for estimating the power distribution of the whole core, it is impossible to reflect the estimation on the power control.
The estimation which takes a lot of time may be explained by the fact that the number of points or locations to be monitored is excessively large. For example, in the case of a nuclear reactor of 1,100,000 KW class, as many as 43 strings of local power range monitors (hereinafter referred to also as LPRM) are distributed at various locations of the reactor cores as viewed in a plan, wherein calculations in accordance with equations (1) and (2) stated hereinafter are executed for all the LPRM strings, which necessarilly results in a great time consumption. In equations (1) and (2), J represents identification number 1 to 4 of four fuel rods (fuel assembly) disposed around each LPRM string, and K represents an index identifying a given one of 24 positions distributed along the fuel rod in the longitudinal or heightwise direction thereof. Accordingly, when the equations (1) and (2) are to be executed for all the points to be monitored (also referred to as the monitoring points), execution of as many as 43.times.4.times.24 times of arithmetic operation is required. Moreover, since equation (1) includes iteration, a lot of time is required even when a computer is used for the calculations.